The
influence of age and sex on the heamatological values of goats and sheep
studied in the arid zone of BornoState of Nigeria. Age and sex
remarkable influence (P<0.05) on the red blood cell (RBC) counts of goats.
Age influenced (P<0.05) the haemolglobin (HB) and the packed cell volume
(PCV) values. Age and sex greatly influenced (P<0.01) the mean corpuscular
volume (MCV) values. Mean corpuscular haemoglobin concentration (MCHC) was
influenced by age. Lymphocytes constituted more than 60% of the total white
blood cell (WBC) counts in male and female goats. Neutrophill and eosinophil
counts were influenced by sex and age. Sex influenced (P<0.05) monocyte and
lymphocyte values in goats. Sex and age influenced (P<0.05) the RBC values
in sheep. PCV and MCHC values of sheep were influenced (P<0.05) by both age
sex. The MCV was influenced (P<0.05) by age. Sex significantly influenced
(P<0.05) the total WBC and monocyte counts.

Small ruminants (Sheep and goats) are one of
the domestic animals of they inhabitants of Borno state and they provide meat,
milk hides and skin. It has been reported that regardless of age, sex and
climate, sheep and goats reared under traditional husbandry system have low
haematological values compared to those reared under modern husbandry (Coles,
1980; Schalm et al, 1975). Low nutritional grassland pasture, stress,
purturition and climatic factors greatly alter the blood values of goats and
sheep (Anosa and Isoun, 1978, Radostits et al 1994).

Blood is an
important and reliable medium for assessing the health status of individual
animals (Oduye, 1976). Much work has not been done on haematological values of
goats and sheep in the arid zone of Borno States especially as it applies to
sex and age. Therefore, this paper focused on the haematological values of
apparently healthy sheep (Balami and Ouda breeds) and goats (Red Sokoto and
Borno White breads) as influenced by age and sex in Borno State, of Nigeria.

MATERIALS AND METHODS

The goats and sheep used in this
study were obtained from the University of Maiduguri animal farm and various
quarters in Maiduguri metropolis especially Kasuan
shanu area. The animals were apparently healthy. Faecal sample from each
animal was collected and examined for the presence of helminth ova using
floatation method (Basu, et al, 1994, Uqurhart et al, 1992). 5
mls of blood was collected from each animal from the external jugular vein
following proper restraint by the owners or attendants and with minimal
excitement. The blood was collected in ethylene diamine tetracetate (EDTA)
vacutainer tubes and transported to the laboratory for analysis. The samples
were analyzed within two hours collection.

All animals with lesions, gastrointestinal or
haemoparasites were excluded from the study. The animals were grouped as shown
in Table 1.

RESULTS

The haematological (mean ± SD) of the
goats are presented in tables 2A and B. The RBC counts in the males range
between .79 ± 0.24 to 9.44 ± 0.33. The RBC was high at birth (0-3 months) and
decreased as the animal grew and later increased especially when the animal was
above 7 years, particularly more so in the males.

In the female, on the other hand, the
value was low 0-6 months and increased between 6 to 9 months and later
fluctuated with age. The value ranged from 6.12 ± 0.62 to 7.25 ± 0.32. Age and
sex had significant influence (P<0.05) on the RBC values of goats.

The Hb concentration increased with age
in both sexes and later fluctuated. The highest value was recorded in both
sexes and later fluctuated. The highest females at 2 to 3 years of age. Age had
influence (P.05) but sex did not have significant influence on the HB
contraction of goats. The PVC fluctuated at early age (0-12 month) and
gradually increased with age up to 2 to 3 years in the females on the other hand
the value fluctuated with age. Highest value was recorded in both sexes at
2 to 3
years of age. Sex had no significant influence but age did influence [ p

The total WBS counts range was 10.45 ± 0.26 and
10.86 ± 0.35 to 14.36 ± 0.97 in males and females respectively. The highest
value in males and females was observed at 3 to 5 years and 6 to 9 months
respectively. In the males, the relative differential leucocyte counts (DLC)
showed 62% lymphocyte, 24.8% neutrophil, 7.8% eosinophil and monocyte 5.1%, and
21.8% neutrophil, 7.8% eosinophil and monocyte 5.4%. In the females on the
other hand, iit was eosinophil 7.1%, monocyte 5.1%, and 21.8% and 66.0% for
neutrophils and lymphocytes respectively. Age showed significant (P < 0.05)
influence on the WBC values of goats. The absolute lymphoocyte counts increased
with age in the males. Similarly, absolute neutrophil counts followed the same
trend and reached the peak at 1 to 2 years of age. Eosinophil and monocyte
absolute counts showed gradual decrease with age to some extent and later
fluctuated. There was sharp increase in the absolute lymphocyte counts in the
females from 6 to 9 months
and later the value fluctuated.

Absolute
neutrophil count fluctuated with age and the highest value was recorded at 3
to
5 years, while the lowest value was seen at birth (0-3 months). Eosinophil
counts gradually decreased with age and the highest and lowest values were
obtained at 0 to 3 months and 5 to 7 years respectively. On the other hand,
absolute monocyte counts increase from 0 to 9 months and later decreased. The
highest value was witnessed at 6 to 9 months while the lowest value was seen at
2 to 3 years. Sex had influence (P < 0.05) but age had no influence on the
absolute neutrophil and eosinophil counts in goats. Age had no influence on
monocyte counts but sex had (p < 0. 05).

Sheep

The
heamatological values (mean ± SD) are presented in table
3A and 3B. In the
males, the RBC counts fluctuated from 6 months to 7 years and the highest value
was recorded at 3 to 6 months. The females showed highest value at 0 to 3
months of age and from 6 months and above. The value decreased remarkably (P
< 0.05). The value at birth (0-3 months) in females is higher than the male
value. Age and sex showed significant influence (P < 0.05) on the RBC counts
of sheep. The Hb concentration increased from 0 to 6 months in males and later
fluctuated. The highest value was witnessed at 9 to 12 months while the lowest
value was seen as from 7 years and above. Females did not show consistency in
the value and at 9 to 12 months of age, the highest value was recorded from 7
years and above.

The Hb was
significantly (p<0.01) influenced by age. The PCV in males showed gradual
increase with age and this increase became significant at 6 to 12 months. The
value reached the peak at 3 to 5 years of age and later, decreased gradually
and fluctuated. Lowest value was seen at birth (0-3 months) similarly, the
value increased with age in females up to 3 years of age. Highest value was
seen at 2 to 3 years and the lowest value was obtained at 7 years and above.
In the sheep, age and sex exhibited remarkable influence (P < 0.05) on the
PCV value. The MCV value in males increased remarkably with age up to 2 to 3 years. The
value in the females fluctuated. The highest value in both males and females
was seen at 2 to 3 years of age. On the other hand, lowest values were
observed in males and females from 0 to 3 months and 3 to 6 months
respectively. In sheep, age had a significant influence (P < 0.05) on the
MCV values. The MCHC values fluctuated with age in both sexes. Highest value
was recorded from 0 to 3 months in both sexes. Both age and sex had remarkable
influence (p < 0.005) on the MCHC value of sheep.

The total WBS
counts range in males and females is between 11.86 ± 1.86 to 16.17 ± 0.98 and
10.92 ± 1.01 to 13.82 ± 0.79 respectively. In the males, the highest value
was obtained at 9 to 12 months of age while the lowest value was witnessed a 5
to 7 years of age. In the females on the other hand, the lowest and highest
values were obtained at 6 to 9 months and 0 to 3 months of age respectively.
Age showed no significant influence but sex had an influence (P < 0.05) on
the total WBC counts.

The relative DLC
indicated in the males, 58.62% lymphocyte, neurtrophil 33.5%, eosinophil 3.8%
and moncyte 4.3%. In the females, it was lymphocyte 55.0%, neutrophil 37.4%,
eosinophil 4.7% and monocyte 4.3%. In the females, it was lymphocyte 55.0%,
neutrophil 37.4%, eosinophil 4.7% and monocyte 2.9%. In the absolute DLC there was
gradual increase with age in lymphocyte counts in males at early age (0  12
months) and as the animals grew in age the values fluctuated. Highest and
lowest absolute lymophocyte counts were seen at 9 to 12 months and 3 to 5 years
of age respectively. In the females, the highest count was seen when the
animals were between the ages of 1 and 2 years. Lowest count was obtained when
they were more than 7 years. Age showed no significant influence but sex had an
influence (P<0.05) on the total WBC counts.

The relative DLC
indicated in the males, 58.62% lymphocyte, neutrophil 33.5%, eosinophill 3.8%
and monocyte 4.3%. In the females, it was lymphocyte 55.0%, netrophil; 37.4%,
eosinophil 4.7% and monocyte 2.9%. In the absolute DLC, there was gradual
increase with age in lymphocyte counts in males at early age (0 12 months) and
as the animals grew in age the values fluctuated. Highest and lowest absolute
lymphocytes counts were seen at 9 to 12 months and 3 to 5 years of age
respectively. In the females, the highest count was seen when the animals were
between the ages of 1 and 2 years. Lowest count was obtained when they were
more than 7 years. Age had no influence (P < 0.05) but sex showed an
influence (P < 0.05) on the lymphocyte counts. The absolute neutrophil
counts in both sexes fluctuated with age. Highest value was recorded at birth
(0 3 months) in both sexes. Lowest value in males and females were obtained at
1 to 2 years and 5 to 7 years of age respectively. Both sex and age did not
have influence (P <0.05) on the neutrophil value. Absolute eosinophil and
monocyte counts fluctuated. In the males and females, the highest eosinophil
count was obtained at 9 to 12 months and 0 to 3 months of age respectively,
while the lowest count in the males and females was witnessed at 5 to 7 years
and 6 to 9 months of age respectively. Both age and sex exhibited remarkable
influence (P > 0.05) on the eosinophil counts. The monocyte count in males
was highest at 9 to 12 months and lowest at 2 to 3 months. In the females on
the other hand, the lowest and highest values were witnessed at 5 to 7 years
and 1 to 2 years of age respectively. In sheep, sex had influence (P < 0.05)
on the monocyte values but age did not.

In both species
of animals, the Hb content was very high (P <0.01) at 2 to 3 years. The Hb
concentration of goats was higher than that of sheep (P < 0.05). The male
values are generally higher (P < 0.05) than the female values. In WBC
values, males recorded in both species. Goats showed lower PCV values than
sheep (P < 0.05). Male animals generally exhibited higher (P < 0.05) PCV
values than female animals. Goats showed higher MCV values (P <0.05) than
sheep in both species, males recorded higher (P <0.05) MCV values than
females. The MCHC value of goats was higher (P< 0.05) than that of sheep.
Males exhibited higher lymphocyte counts than females in both species (P<
0.05).

DISCUSSION

The RBC, Hb, PCV,
MCV, MCHC and WBC values obtained in this study in both sexes in goats and
sheep were comparable to those previosly reported (Sarror and Schil, 1977;
Anosa and Todd et al, 1952; Oduye, 1976; Holman; 1944a; Holman and Dew, 1965a;
Schalm et al, 1975). In both species, high RBC counts was recorded in early
life ( 0- 6 months) of the animals when compared to the adult values and this
was in agreement with the observations of Holman and Dew (1964) and Schalm et
al., (1975). The high RBC values in the young ruminants in this study may among
other things be due to excitement or strenuous exercise during handling
(Gartner et al., 1969). This leads to the release of adrenaline and hence
spleen contracts and this causes the release of more RBC into circulation. It
is only psychological tranquillisation that can reduce the splenic influence
(Schalm et al., 1975) and this can only be achieved by holding the animal for
15-20 minutes by the owner or sympathetic attendant before sexes of goats and
increased in the first few with the observations of other workers (Schalm et
al., 1975), who reported that the Hb and PCV values decreased during the first
week of life; then stablished with a slight downward trend, during the first
few months and later increased as age increased. It might be pertinent to note
that the difference in the present workers may be due to breed difference,
management and environmental factors. The MCV and MCHC values in both species
fluctuated and their values are dependent upon RBC, Hb and PCV values.

Goats showed
higher neutrophil values than sheep and in both species, males exhibited higher
neutrophil counts than female (P <0.05). Goats had higher eosinophil counts
than sheep (P <0.05). It was observed in this study that both sexes of both
species of animals showed high number of WBC in the first few months of life,
and this agrees with previous work (Schalm et al., 1975). Tropical environments
are known to be havens of parasites and high WBC counts in the young ruminants
may probably be due to environmental disposition. The white blood cells (WBC)
are the soldiers of the body and their high counts may also be due to increase
or complement the immune systems o the animals at the early stage of life which
they may not obtain from the colostrum of the dam (Coles, 1980; Schalm et a;.,
1975). It may also be attributed to physiological phenomenon i.e. excitement
or
strenuous exercise during handling (Coles, 1980).

The lymphocytes
constituted majority of the WBC counts and the cells increased with age in
early life in both sexes of both species of animals. The high lymphocyte counts
in the animals in this study are favoured by the findings of Milson et al.,
(1960) and Wilkins and Hodges (1962) and it might be attributed to stress and
immune response to the environment (Cole, 1980) which harbours various
detectable and undetectable parasitic and or bacterial organisms.

The total mean
WBC counts in male and female sheep in this study ranged between 11.8 ± 1.86
to
16.17 ± 0.98 and 10.92 ± 1.01 to 13.82 ± 0.79 respectively. The total WBC in
sheep in this study in some ge groups are higher than the value (4,000 
12,000) reported by Holman (1944b), who recorded 13,000 as slight leucocytes.
Similarly, the total mean WBC counts range in male and female goats is 10.45 ±
0.19 to 15.91 ± 0.26 and 10.86 ± 0.35 to 14.36 ± 0.97 respectively. The range
agrees with the one (6,000  16,000) reported by Schalm et al., (1975) but was
lower than the value (19,180) reported by Holman and Dew (1965b) in individual
animals by the 4th month. Since the animals are apparently healthy,
any value beyond the upper limit in any of the sex in both species may be
regarded as leucocytosis and any vale below the lower limit may be termed
leucopaenia.

In conclusion,
age group and sex showed remarkable influence on the haematological values of
small ruminants in the arid zone of BornoState. The values
obtained are comparable to values recorded elsewhere. There was fluctuation in
all the hematological parameters of both species of animals. What cause the
fluctuation in various parameters may be undetected minor infections, weather
extremities and poor management in this area, since the economic hardship is
on
the advanced stage and most of the farmers are very poor. They have to attend
to themselves first feeding wise before attending to their animals.

ACKNOWLEDGEMENT

The authors are
grateful to Mr. Benson Okeh, Ismaila A. Gadaka for their technical assistance;
Dr. I.O. Igbokwe for his useful criticism and University of Maiduguri farm
manager for his cooperation.